U.S. patent number 4,986,473 [Application Number 07/238,129] was granted by the patent office on 1991-01-22 for crop sprayer shield.
Invention is credited to D. Gavin Semple, Donald J. Vass.
United States Patent |
4,986,473 |
Semple , et al. |
January 22, 1991 |
Crop sprayer shield
Abstract
The conventional spray shield for use on crop sprayers includes
a large cover for the entire spray boom. The cover extends
downwardly to the top of the crop being sprayed, and consequently
impedes access to the spray nozzles and hides the spray pattern.
Thus, the operator of the sprayer is not aware of blocked nozzles.
A solution to the problem is to provide individual spray hoods over
each nozzle, the hoods having essentially the same shape as the
spray produced by the nozzle, i.e., conical with an elliptical
horizontal cross section at the discharge end. The hoods are
sufficiently short that they terminate above a crop in the use
position, so that the sprays are visible and the nozzles are
readily accessible.
Inventors: |
Semple; D. Gavin (Craven,
Saskatchewan, CA), Vass; Donald J. (N. Regina,
Saskatchewan, CA) |
Family
ID: |
25624916 |
Appl.
No.: |
07/238,129 |
Filed: |
August 30, 1988 |
Foreign Application Priority Data
Current U.S.
Class: |
239/109;
239/288.5 |
Current CPC
Class: |
A01M
7/0064 (20130101); B05B 1/28 (20130101) |
Current International
Class: |
A01M
7/00 (20060101); B05B 1/28 (20060101); B05B
001/28 () |
Field of
Search: |
;239/103,104,150,288.3,288,288.5,159,499,504,518 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Kashnikow; Andres
Assistant Examiner: Forman; Michael J.
Attorney, Agent or Firm: Seaby; George A.
Claims
We claim:
1. A spray shield for agricultural crop spraying equipment of the
type including a spray boom for carrying liquid to be sprayed and a
plurality of spaced apart nozzles for discharging liquid from the
boom, the shield comprising hood means including a cylindrical neck
for mounting on the boom in surrounding relationship to a nozzle,
and a substantially elliptical body flaring downwardly and
outwardly from said neck, said elliptical body having essentially
the same shape as the spray pattern produced by the nozzle so as to
maintain the integrity of the spray pattern from the nozzle and
through the elliptical body, the height of the shield being such
that the bottom end thereof is above the crop being sprayed during
use of the shield, whereby the spray from the nozzle is protected
from the wind while being at least partly visible to the spraying
equipment operator.
2. A spray shield according to claim 1, including alignment means
for ensuring that said hood means is properly aligned with said
nozzle and that all said hood means are aligned with each other on
the spray boom.
3. A spray shield according to claim 2, including disc means for
mounting said hood means on the boom, and nozzle locating means in
said disc means defining said alignment means.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a spray shield for use on crop spraying
equipment.
The conventional crop or field sprayer includes a boom assembly
attached to a trailer and extending outwardly from both sides
thereof in the spraying position. The boom assembly includes an
elongated pipe or boom carrying a plurality of spaced apart
nozzles, each having a spray tip for dispensing liquid. The
currently preferred flat fan spray tip distributes the liquid in an
elliptical pattern, the major axis of which is inclined with
respect to the axis of the boom. When a plurality of such tips are
spaced equidistant apart along the length of the boom, the spray
patterns formed by the tips overlap but do not interfere with each
other. Because the patterns flare or fan out, overlap without
interfering with each other and are spaced equidistant apart, the
spray can be distributed along the length of the boom with a plus
or minus 5% variation in spray tip output.
On the other hand, because the droplets are so small, they can
readily be deflected from their normal pattern by a wind of 10
km/hr or greater. Spray distribution can easily be disrupted to
reach unacceptable levels, i.e. an unacceptably large crop area is
missed by the spray. Because of the relatively short spraying
season, it is almost inevitable that spraying must sometimes be
done during unfavorable windy conditions.
2. Discussion of the Prior Art
One solution to the above mentioned problem is to provide a spray
cover or hood over all or most of the boom structure. Such solution
is proposed, for example by U.S. Pat. No. 3,512,714, which issued
to M. E. Phelps et al on May 29, 1970. The Phelps et al and other
commercially available spray hoods either contact or come close to
the top of the crop being sprayed to ensure minimal wind
interference with the minute droplets. Thus, such devices possess
the disadvantages that they are large, cumbersome and expensive to
produce. Moreover, the hoods extend so far from the boom that the
spray nozzles and tips are not readily accessible, and there is no
way of knowing when a nozzle or tip becomes plugged because the
spray patterns are not visible.
The object of the present invention is to solve the above-mentioned
problems by providing a relatively simple, economical spray shield,
which substantially reduces wind interference with a spray pattern
while still permitting access to the spray nozzle or tip.
GENERAL DESCRIPTION OF THE INVENTION
Accordingly, the present invention relates to a spray shield for
use on crop spraying equipment of the type including a spray boom
for carrying liquid to be sprayed and a plurality of spaced apart
nozzles for discharging liquid from the boom, the shield comprising
substantially conical hood means of essentially the same shape as
the spray pattern produced by a nozzle for mounting on the boom and
for extending downwardly therefrom into surrounding relationship to
the nozzle.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in greater detail with reference to
the accompanying drawings, which illustrate a preferred embodiment
of the invention, and wherein:
FIG. 1 is a schematic perspective view of a section of a spray boom
without spray shields;
FIG. 2 is a schematic perspective view of the section of spray boom
of FIG. 1 with spray shields in accordance with the present
invention mounted thereon;
FIG. 3 is a plan view of a spray shield in accordance with the
present invention;
FIG. 4 is an exploded, side elevation view of the spray shield of
FIG. 3; and
FIG. 5 is an exploded end view of the spray shield of FIGS. 3 and
4.
DESCRIPTION OF PREFERRED EMBODIMENT
With reference to FIG. 1 the conventional crop spraying equipment
includes an elongated pipe or boom 1, which is pivotally connected
to a trailer (not shown) for extension outwardly therefrom to the
spraying position shown in FIG. 1. A plurality of nozzles 2 are
provided on the boom 1. The nozzles 2 are spaced equidistant apart,
and include spray tips 3 for producing an elliptical cone 4 of
liquid, i.e. a generally conical liquid spray, a horizontal section
or plane of which is elliptical. The cones 4 produce elliptical
patterns 5 of the fine droplets of liquid on a crop. The major axes
of the patterns 5 are inclined with respect to the longitudinal
axis of the boom 1, and the patterns 5 overlap without interfering
with each other so that the crop is covered uniformly and more or
less completely during passage of the spray device thereover.
In the absence of any spray shield or cover, the cones 4 and small
liquid droplets would be affected by the wind, which adversely
affects the spray pattern. In order to reduce or negate the effect
of the wind, an individual shield generally indicated at 6 is
provided on each nozzle 2. The shield 6 extends downwardly from the
boom 1, but stops above the top surface of the crop, so that the
spray cone 4 can be seen by the operator of the sprayer.
Referring to FIGS. 3 to 5, each spray shield 6 includes a generally
conical hood 8 of more or less elliptical cross section throughout
its height. The hood 8 tapers upwardly to a cylindrical neck 9,
which surrounds a nozzle 2 (FIG. 4) when the shield is mounted on
the boom 1.
The neck 9 extends upwardly to the top of the boom 1. A concave
groove 11 is provided in the top end of the neck 9 for receiving
the boom 1, so that the boom 1 can be sandwiched between the top of
the neck and a disc 14. The disc 14 is attached to the top end of
the neck 9 by screws 15 extending into aligned threaded holes 17
and 18 in the disc 14 and the neck 9, respectively. The disc 14 is
attached to the nozzle body 2 using nozzle body screws 19, which
extend through aligning holes 20 (FIGS. 3 and 5) in the disc 14 to
ensure proper alignment of the hood 8 with respect to the boom
1.
During normal operation, the shield restricts the spray cone 4
(FIG. 2) to the desired generally conical shape. Because the
distance between the bottom of the hood 8 and the crop is small,
the spray droplets forming the cone 4 are, at worst, only slightly
affected by wind conditions. While the dimensions are not critical,
typically, the total height of the shield is approximately 83/4
inches, the width of the hood 8 as viewed from the end (FIG. 5) is
approximately 41/4 inches, and the length of the hood, i.e. the
length of the major axis of the bottom of the hood is approximately
18 inches. The most widely used fan tips 3 have an 80.degree. to
110.degree. spray angle. The recommended distance from the tip to
the top of the crop or the target is 10 to 19 inches. The distance
from the tip 3 to the bottom edge of the hood 8 is 5 to 6 inches.
Consequently, the spray is visible to the sprayer operator for from
5 to 14 inches. If a tip 3 becomes plugged, the tip is readily
accessible for cleaning by reaching into the hood 8. The hood is
typically offset, i.e. inclined with respect to the boom 1 by
10.degree. for alignment with the spray cone.
It will be appreciated that the shield structure described
hereinbefore can be installed on existing crop spraying equipment,
without alterations to such equipment. The spray shield is produced
using a light polyethylene plastic which is rotationally molded,
but other materials can be used.
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